Fluid power unit



May `25, l948. E; MccoRMlcK FLUID POWER UNIT Filed Aug. 13, 1945 2Sheets-Sheet 1 4f! Si INVENTOR. ELMER MCCORMICK ATTURNEYS.

Patented May 25, 1948 OFFICE FLUID POWER UNI'r Elmer McCormick,Waterloo, Iowa, assigner Deere Manufacturing Co., a corporation of IowaApplication August 13,1945, serial No.'s1o,5az

l The present invention relates generally to uid power units and moreparticularly to units oi the type comprising a cylinder and a pistonslidable axially therein. such as is used for moving a load inconnection with a hydraulic or pneumatic control system. The particularembodiment which IV have Jin'mindl-is a hydraulically actuated cylinderioruse in power operated control oi implements associated with atractor, although I do not intend my inventionto be limited to thisparticular embodiment. Hydraulic Acontrol systems of this general typeare used for shitting an implement, such as a cultivator, plow, or thelike, from a normal working position in engagement with the ground to araised transport position, and vice versa. Some implements are mounteddirectly upon 'the tractor, while othersare mounted on their own wheelsin trailing relation to the tractor, but in either case` they areprovided with an actuating lever to-which a control cylinder and pistonassembly can be connected for controlling the implement.

As is well known to those skilled-in the art, it is desirable to adjustthe implement to a predetermined depth oi operation in the ground, as inthe case of a cultivator or plow, or a predetermined elevation above theground, as in the case of a harvesting implement, to which position theimplement automatically returns each'time it is lowered out of theraised transport `position.

The principal object of my invention relates to the provision of a fluidpower unit in which is incorporated an adjustable limit stop iorpositively determining the extent of relative movement between thepiston and cylinder members.

Another object relates to th provision oi a iluid actuated piston andcylinder assembly with an axially adjustable device for limiting theextent oi movement of the piston as it moves into the cylinder. 1

My invention can be applied either to cylinders of the single actingtype in which iluid pressure is applied only to one side of the pistonwhen raising the implement, while the weight of the implement is used toreturn the piston to a normal working position in the cylinder when theimplement is lowered, or to a double acting piston and cylinder assemblyin which the fluid pressure can be applied to either side of the piston,selectively, thus providing for applying `pressure when lowering theimplement, to force the latter to the ground. In the latter case, the

adjustable limit stop is adapted to positively f4 Claims. (Cl. 121-38)used in connection with a hydraulic circuit provided with means forrelieving the pressure in the cylinder when the pressure exceeds anormal value, as is well known to those skilled in the These and otherobjects and advantages oi my invention will be Aapparent to thoseskilled in the f art after a consideration of thefollowing descriptionIin which reference is had to the d-rawings appended hereto, in whichFigure 1 is a top plan view of a double acting piston and cylinderassembly' embodying the principles of the-present invention:

Figure 2 is a side elevational view of the fluid power unit, a portionof the mounting bracket being broken away to show the details ofconstruction;

Figure 3 is a sectional view taken along a line 3-3 in Figure 2 anddrawn to an enlarged scale; A

Figure 4 is a sectional elevational view, taken along a line 4-4inFigure 1: and

Figure 5 is an end view taken along a line 5-5 in Figure 4.

Referring now to the drawings, the iluid'power 'unit comprises acylinder member and a piston member, indicated generally by referencenumerals III, il, respectively. The cylinder member ill contains acylindrical pressure chamber I2, within which the piston member l I isslidable axially. The member I0 is preferably in the form of a. castingand has a cylinder head portion I3, preferably formed integrallytherewith at one end of the pressure chamber I2. The opposite end of thepressure chamber i2 is closed by means of a detachable cylinder head i4,which is secured by bolts I5 to a ange I6, formed integrally with thecylinder casting.

The piston member II comprises a piston 20 mounted on one end of apiston rod 2i, which extends axially out through an opening 22 in theclosed end I3 of the cylinder. The opening 22 is sealed by means of asealing gland 23, which is secured within an annular recess 24surrounding the rod 2i. The gland 23 is compressed within the recess 24by means oi' a retaining member 25 secured by bolts 26 to the end of thecylinder member III.

The piston 20 comprises a metal sleeve 30 mounted on an end portion 3lof the rod 2i, turned to a reduced diameter. 'I'he sleeve 30 has aradially extending annular flange 32, which ts slidably within thecylinder I2 and supports a pair of annular sealing members 33 onopposite sides thereof, respectively. The sealing members are retainedadjacent the nange 32 by means of a pair of retainers Il, one ci whichbears against 3 a washer and the other of which bears against the piston20 together against a shoulder 31 on the rod 2 I. l

ll'luid.y Preferably oil, is supplied to the leit side of the piston 20,as viewed in Figure 4, through a portr4ll inthe detachable head I4. Theport 40 is threaded to receive a suitable iltting (not shown) by whichan oil supply line can be attached to the cylinder.

' apertures 68 in the lugs 86 for thepurposeof pivotally connecting theconnector 85 to any suitable operating lever or mounting ear (not shownlon the tractor or on the associated implement.` The coupling pin 61 issecured in the connector $5 by means of a latch pin S9, which is similarFluid is suppliedto the cylinder on the right` side oi the pistonthrough a second port 4I, formed in an extension 42 of the cylindercasting IIl and threaded to receive a suitable Aoil line ntting.passageway 43 is cored within the casting' -extension 42 andextendsaxially along the side of the pressure chamber I2 and' communicates withthe latter through an opening 44 at `the opposite end of the chamber I2.

Thus, it is evident when `iluid under pressure is supplied through theport III and iluid is allowed to escape through the port 4 I the pistonmember n Conversely, when pressure is applied to the port 4I and iluidis released from the port 40, the piston member II will move toward theleft in the cylinder member I0. An aperture 45 is provided in the outerwall of the passage 43 opposite the opening 44 for the purpose ofletting the air out of the cylinder and also for cleaning the cylinderchamber I2 and passage 43, and the aperture 45 is threaded to receive aplug 46 which normally closes the aperture.

The cylinder member I0 is provided with supporting means in the form ofa pair of laterally spaced lugs Ell, formed integrally with thedetachable cylinder head I4 and provided with a pair of transverselyaligned holes 5I adapted to receive a mounting pin 52. 'I'he lugs SIIare spaced apart to receive therebetween a suitable mounting ear (notshown) on the tractor or on an implement associated therewith. the pin52 being adapted to secure the lugs to the ear. The pin 52 is secured inposition in the apertures 5l by means of a latch pin 53 disposed withina recess 54 which intersects the aperture 5I in one of the lugs SII. Thepin 52 is provided with a neck portion 55 of reduced diameter, adaptedto register with the socket S4, so that the latch pin 53 lies within theannular groove 85 to lock the pin $2 against longitudinal movementwithin its apertures 5I. The latch pin 53 is also provided with anannular groove 56 which can be moved into register with the aperture 5Iby sliding the latch pin 53 within its socket 54. thereby releasing thepin 52 and providing for moving the latter out of its apertures 5I.Normally, the latch pin 6I is held in locking position by means of acoll spring 58 seated within a recess in the latch pin IIr `will movetoward the right4 in the lcylinder Ymember Il.

to thelatch pin 58 at the otherend oi'the cylinder, and since thedetails oi construction and manner of voperation are similar to thosedescribed in connection'with latch pin 53, a rep'etition thereof isconsidered unnecessary.

The iluid power unit is usually mounted on the tractor or on animplement drawbar by means oi the coupling pin 52; while the couplingpin I1 is usualLv employed for connecting the connector to a control orlifting lever, so that the implement is raised to transport position bythe piston moving outwardly, or to the right, as viewed in Figure 4.Conversely, the implement is lowered by moving the piston 2li inwardlytoward the left same working position each time that it is lowered, suchas, for example, when the cultivator or 53 and bearing against theend ofthe recess 54. I

A securing pin 59 is inserted through a hole GII. which intersects therecess 54 in such a position that the pin S9 lies transversely in thegroove 56 of the latch pin 53. thereby preventing the latter from beingpushed out. of its socket 54 by the spring 58. Normally, however; theouter end il of thelatch pin 53 projects from the socket 54 and servesas a push but-tonto shift the. latch pin 53 inwardly of the socket 54 tounlock the pin S2.

The outer end of the piston rod 2| is provided with a bifurcatedconnector G5. rigidly secured to the end of the rod 2| and provided witha pair of laterally spaced mounting lugs 66. A coupling plow is loweredat the beginning of each row or furrow.-

According to the present invention, this is ac;

compllshed by means oi' an adjustable limit stop, indicated generally byreference numeral 10, and

which comprises a transverse yoke member 1I,

provided with a centrally4 disposed opening l2, through which the pistonrod 2I slidably extends to the connector 65, which is disposed on therod 2 I outwardly of the yoke 1I. The yoke 'II includes a pair ofoppositely extending legs 13, each of which has an aperture I4 disposedparallel with the piston rod 2 I, and each oi which receives the reducedend portion 'I5 oi a supporting rod 16 provided with a shoulder I1engaging the inner surface of the leg, the outer end of the threadedportion l5 receiving a nut 'I9 and lock washer 18. Thus, each of thesupporting rods I8 is rigidly secured to its leg portion .13 of the yoke1I, and the two rods 16 extend along opposite sides of the cylinder IIl, respectively. 'I'he supporting rods 16 are received within a pair ofsleeve portions having passages 86 therein parallel with the piston rod2|. 'Ihe rods I6 are slidable axially through the passages 86, to adjustthe yoke II axially relative to the cylinder I0.

Each of the rods 'I6 is provided with a row of longitudinally spaced,radially extending holes 81. The sleeve portions 85 are also eachprovided with a row of longitudinally spaced, radially lextending holes88, which can be brought into align-'- ment with the holes 81 byshifting the yoke 1I and rods I6 axially oi the cylinder. However, thespacing between the holes I8 in the sleeve 85 is i diil'erent from thespacing between the holes il each pair cf-augned apertures s1, as to nxthe 'h yoke 'II in axially adjusted position.

Each oi the pins is provided with a spring pin 61 is inserted throughtransversely aligned 75 clip SI in the form oi a lea! spring attached toportions 85 of the cylinder.

tions ll to hold the pins 9| in the latter and bending at right anglesto lie along the sides of the sleeve The ends of the spring clips 9iarebent inwardly at 92 to engage under the sleeve portions B andhold thepins l vSil within the holes 88.

` i the porc 4o and snowing the num to be re1easea from the port 4i.'Ihe piston 2li is free to move until the washer 3l engages the closedend portion I3 oi' the cylinder. The piston 2n is moved toward the leftby applying iluld under pressure to the port 4l and releasing fluid fromthe port `40. The piston 20 continues to move until the connector 65engages the yoke 1 I, which is rigidly attached to the cylinder lli bymeans of the pins 90 inserted through aligned apertures l1, 8l in thesupporting rod Il and the integrally formed sleeves 'llin the cylindercasting. The yoke 'H can be shifted axially of the cylinder I0 toadjustthe terminal position of the piston 26 in'.

which the connector 6l engages the yoke 1l, by

removingthe pins 90 and shifting the yoke axial-` 1y to bring otherApairs o! apertures l1. 8l into alignment, alter which the pins ll arereinserted into the aligned apertures and the'spxing clips li aresnapped into engagement with the sleeve porposition. I claim:

1. A iiuid power unit comprising a cylinder member. a piston memberslidable therein and having a connecting rod extending out oi one end ofthe cylinder member, and adjustable means limiting the movement of saidpiston member in said cylinder comprising a lyoke disposed of saidconnecting rod and provided `with an opening through which said rodextends and is shiftable therethrough, stop means on said rod extendingradially oi' the latter beyond the edge o( said opening to engage saidyoke in one direction ot movement, a pair oi supporting rods rlgidbattached to said yoke and extending longitudinally along oppositesidesvoi said cylinder member, respectively, means on opposite sidesof'said cylinder member apertured to slidably receive said supportingrods, respectively, and means for releasably securing at least one ci.'said supporting rods to 'said apertured means in longitudinally adjustedposition.

2. A nuid power unit comprising a cylinder l member, a piston membersudable therein and having a connecting rod extending out of one end ofthe cylinder member, and adjustable means limiting member in saidcylindercomprising a yoke disposed transversely of said connecting rod.-stop means `on said rod engageable with said yoke in one direction ofmovement, a pair o! supporting rods rigidly attached to said yoke andextending longitudinally along opposite sides of said cylinder member.respectively, means on opposite sides of said cylinder member aperturedto slidably receive said supporting rods, respectively. and means forreleasably securing at least oneo! said supporting rods to saidapertured means in longitudinally adjusted position, said securing meanscomprises a pin, one of said 811990111118 rodshaving a row or axiallyspaced, radiallyet- 75 tending apertures adapted to receive said pin andsaid apertured rod receiving means having a plurality of aperturestransversely intersecting the rod receiving aperture and adapted toregister with said apertures in said rod by shifting the ylatter axiallyof said cylinder, the spacing between said apertures in said rodreceiving means and in said rod being different in order to, ob-

tain a vernier adjustment of said yoke longitudinally of said cylinder.

3. A nula power unit comprising a eyiiinder-4 member, a. piston memberslidable therein and having a connecting rod extending out of one end ofthe cylinder member and a vconnector at the outer end of said rod, andadjustable means limiting the movement of said piston member in saidcylinder comprising a yoke disposed transveisely of said connecting rodand provided with an opening through which said rod extends and isshiftable therethrough, said connector being engaged by said yoke whensaid piston moves toe member, a piston'member slidable therein and themovement of said piston 0 having a connecting rod extending out of oneend of the cylinder member and a connector at the outer end of said rod.and adjustable means limiting the movement of said piston member in saidcylinder comprising a yoke disposed transversely of said connecting rodand provided with anopening through which said rod extends and isshiftable therethrough, said connector being engaged by said yoke whensaid piston moves toward the opposite end of the cylinder, a pair ofsupporting rods rigidly attached to said yoke and extendinglongitudinally along opposite sides of said cylinder member,respectively, a

-pair of -axially extending sleeves attached to said cylinder onopposite sides thereof and adapted to slidably receive said supportingrods, respectively, at least one of said rods having a row o!longitudinally spaced radially extending apertures and the associatedsleeve having a-row of apertures extending radially therethrough andalignable with said apertures in said rod, the

spacing between said apertures in. said sleeve and in said rod beingdiirerent in order to obtain a vernier adjustment of said yokelongitudinally of said cylinder. Y

Emma Meconsncx.

REFERENCES CITED The following references are 'of record in the ille ofthispatent:

UNITED STATES PATENTS

